timerfd_settime

timers that notify via file descriptors

sys_timerfd_settime(int ufd, int flags, const struct __kernel_itimerspec *utmr, struct __kernel_itimerspec *otmr)

register	value
`x8`	86, the syscall number
`x0`	int ufd
`x1`	int flags
`x2`	const struct __kernel_itimerspec *utmr
`x3`	struct __kernel_itimerspec *otmr
`x0`	the return value

Then run svc #0 to enter the kernel.

Same syscall on other architectures